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1.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 49(6): 863-869, 2024 Jun 28.
Article de Anglais, Chinois | MEDLINE | ID: mdl-39311782

RÉSUMÉ

Intracranial seminoma is a rare malignant tumor originating from the germ cells, usually occurring in the pineal gland or pituitary gland. In June 2020, the Department of Endocrinology at the First Affiliated Hospital of Army Military Medical University admitted a 20-year-old male patient with an intracranial germ cell tumor and spinal metastases. The patient presented with headache, dizziness, and visual impairment. Enhanced magnetic resonance imaging (MRI) of the head indicated thickening of the pituitary stalk. After multidisciplinary consultation, the patient underwent endonasal transsphenoidal resection of the tumor, with the pathological diagnosis confirming germ cell tumor. The patient received regular radiotherapy postoperatively. One year later, the tumor recurred and metastasized, leading to a second surgery for tumor resection in the thoracic spinal canal, followed by continued chemotherapy. The patient's clinical symptoms, such as headache and visual disturbances, improved, but he continued to experience panhypopituitarism and required long-term hormone replacement therapy. Early diagnosis of intracranial germ cell tumors is challenging, and they are prone to metastasis and highly sensitive to radiotherapy and chemotherapy. Early diagnosis and multidisciplinary comprehensive treatment can help improve the quality of life and prognosis for patients.


Sujet(s)
Imagerie par résonance magnétique , Séminome , Humains , Mâle , Séminome/anatomopathologie , Jeune adulte , Hypophyse/anatomopathologie , Hypophyse/imagerie diagnostique , Hypopituitarisme/étiologie , Tumeurs du cerveau/secondaire , Tumeurs du cerveau/imagerie diagnostique , Tumeurs du cerveau/anatomopathologie , Récidive tumorale locale , Tumeurs de l'hypophyse/anatomopathologie , Tumeurs de l'hypophyse/imagerie diagnostique
2.
Zhongguo Zhen Jiu ; 44(9): 1062-6, 2024 Sep 12.
Article de Chinois | MEDLINE | ID: mdl-39318298

RÉSUMÉ

The paper summarizes Professor JI Laixi's academic thought on acupuncture and moxibustion. Professor JI Laixi inherits and carries forward the theory and technical system of Shanxi "new nine needles", deepens its academic connotation, and promotes clinical practice. He advocates the integration of Chinese and western medicine, and the inclusion of multiple disciplines, e.g. acupuncture and moxibustion of Chinese medicine and modern anatomy. He takes the lead in proposing a new approach to the treatment of meridian diseases of limbs, "treating the neck region for the diseases of head, treating the abdominal region for the diseases of the lumbar region, and treating the lumbar region for the disease of knees". He proposes the acupoint prescription being standardized and simplified, explores the system of acupoint prescription and establishes the prescriptions for gastric diseases, intestinal diseases and antihypertension.


Sujet(s)
Thérapie par acupuncture , Moxibustion , Moxibustion/histoire , Moxibustion/méthodes , Humains , Thérapie par acupuncture/histoire , Chine , Histoire du 20ème siècle , Acupuncture/enseignement et éducation , Acupuncture/histoire , Points d'acupuncture
3.
Nat Commun ; 15(1): 7340, 2024 Aug 26.
Article de Anglais | MEDLINE | ID: mdl-39187536

RÉSUMÉ

Inspired by the natural shape-morphing abilities of biological organisms, we introduce a strategy for creating energy-efficient dynamic 3D metasurfaces through spatiotemporal jamming of interleaved assemblies. Our approach, diverging from traditional shape-morphing techniques reliant on continuous energy inputs, utilizes strategically jammed, paper-based interleaved assemblies. By rapidly altering their stiffness at various spatial points and temporal phases during the relaxation of the soft substrate through jamming, we enable the formation of refreshable, intricate 3D shapes with a desirable load-bearing capability. This process, which does not require ongoing energy consumption, ensures energy-efficient and lasting shape displays. Our theoretical model, linking buckling deformation to residual pre-strain, underpins the inverse design process for an array of interleaved assemblies, facilitating the creation of diverse 3D configurations. This metasurface holds notable potential for tactile displays, particularly for the visually impaired, heralding possibilities in visual impaired education, haptic feedback, and virtual/augmented reality applications.

4.
BMC Bioinformatics ; 25(1): 277, 2024 Aug 27.
Article de Anglais | MEDLINE | ID: mdl-39192184

RÉSUMÉ

Over the past two decades, scientists have increasingly realized the importance of the three-dimensional (3D) genome organization in regulating cellular activity. Hi-C and related experiments yield 2D contact matrices that can be used to infer 3D models of chromosome structure. Visualizing and analyzing genomes in 3D space remains challenging. Here, we present ARGV, an augmented reality 3D Genome Viewer. ARGV contains more than 350 pre-computed and annotated genome structures inferred from Hi-C and imaging data. It offers interactive and collaborative visualization of genomes in 3D space, using standard mobile phones or tablets. A user study comparing ARGV to existing tools demonstrates its benefits.


Sujet(s)
Réalité augmentée , Génome , Imagerie tridimensionnelle/méthodes , Logiciel , Humains , Génomique/méthodes
6.
J Hematop ; 17(3): 129-137, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-38967898

RÉSUMÉ

Epstein-Barr virus (EBV) typically infects B cells in infectious mononucleosis (IM), but a rare case shows EBV infection in T cells. Seven cases of lymphoproliferative disorder caused by EBV-positive cytotoxic T/natural killer (NK) cell proliferation in the lymph nodes, termed IM with transient EBV infection of T and NK cells (EBV + T/NK cells in IM), are reported here. The purpose of the study is to describe clinicopathological features of EBV + T/natural killer (NK) cells in IM of the lymph node. We retrospectively analysed seven cases of Chinese children and young people adults with EBV + T/NK cells in IM. We used morphological observation, immunohistochemical staining, EB virus in situ hybridisation detection, and analysis of T-cell receptor gene rearrangement. The patients were healthy prior to illness, experiencing sudden onset occurring in all the patients, with high fever as the first symptom, followed by lymphadenopathy and hepatosplenomegaly. Diagnosis occurred < 1.5 months of symptom onset. Most lymphocytes in lesions expressed CD3 and Granzyme B or TIA-1 and lacked CD5. CD56 was expressed in numerous cells in 5 of the 7 cases. EBV-encoded RNA (EBER) was detected in medium-to-large-sized cells (50-100 cells per cell/high-power field). T-cell receptor (TCR) gene rearrangement was seen in six cases, with monoclonal rearrangement in four cases. Treatment was conservative treatment but not chemotherapy. Four received anti-HLH therapy and others anti-inflammatory treatment. All patients survived with relapse after long-term clinical observation and follow-up. EBV + T/NK cells in IM can elicit malignant features that mimic T/NK-cell lymphoma pathologically and benign features mimicking IM clinically. These findings indicate that EBV + T/NK cells in IM could serve as valuable diagnosis. Additional clinical information, including age of onset (children and young people), nature of onset (sudden), disease course (short), symptoms (systemic), EBV infection status (acute), and lymph node involvement, is crucial for accurate diagnosis and prognostic evaluation.


Sujet(s)
Infections à virus Epstein-Barr , Herpèsvirus humain de type 4 , Mononucléose infectieuse , Cellules tueuses naturelles , Humains , Mononucléose infectieuse/immunologie , Mononucléose infectieuse/virologie , Mononucléose infectieuse/diagnostic , Mâle , Femelle , Enfant , Adolescent , Herpèsvirus humain de type 4/immunologie , Cellules tueuses naturelles/immunologie , Infections à virus Epstein-Barr/immunologie , Infections à virus Epstein-Barr/virologie , Études rétrospectives , Enfant d'âge préscolaire , Adulte , Jeune adulte , Noeuds lymphatiques/anatomopathologie , Noeuds lymphatiques/immunologie , Noeuds lymphatiques/virologie , Lymphocytes T/immunologie
7.
Cell ; 187(18): 4926-4945.e22, 2024 Sep 05.
Article de Anglais | MEDLINE | ID: mdl-38986619

RÉSUMÉ

Posterior fossa group A (PFA) ependymoma is a lethal brain cancer diagnosed in infants and young children. The lack of driver events in the PFA linear genome led us to search its 3D genome for characteristic features. Here, we reconstructed 3D genomes from diverse childhood tumor types and uncovered a global topology in PFA that is highly reminiscent of stem and progenitor cells in a variety of human tissues. A remarkable feature exclusively present in PFA are type B ultra long-range interactions in PFAs (TULIPs), regions separated by great distances along the linear genome that interact with each other in the 3D nuclear space with surprising strength. TULIPs occur in all PFA samples and recur at predictable genomic coordinates, and their formation is induced by expression of EZHIP. The universality of TULIPs across PFA samples suggests a conservation of molecular principles that could be exploited therapeutically.


Sujet(s)
Épendymome , Épendymome/génétique , Humains , Tumeurs sous-tentorielles/génétique , Tumeurs sous-tentorielles/anatomopathologie , Génome humain , Nourrisson , Tumeurs du cerveau/génétique , Tumeurs du cerveau/anatomopathologie , Enfant , Mâle , Femelle
8.
Mikrochim Acta ; 191(6): 328, 2024 05 14.
Article de Anglais | MEDLINE | ID: mdl-38743383

RÉSUMÉ

The instant screening of patients with a tendency towards developing Alzheimer's disease (AD) is significant for providing preventive measures and treatment. However, the current imaging-based technology cannot meet the requirements in the early stage. Developing biosensor-based liquid biopsy technology could be overcoming this bottleneck problem. Herein, we developed a simple, low-cost, and sensitive electrochemical aptamer biosensor for detecting phosphorylated tau protein threonine 231 (P-tau231), the earliest and one of the most efficacious abnormally elevated biomarkers of AD. Gold nanoparticles (AuNPs) were electrochemically synthesized on a glassy carbon electrode as the transducer, exhibiting excellent conductivity, and were applied to amplify the electrochemical signal. A nucleic acid aptamer was designed as the receptor to capture the P-tau231 protein, specifically through the formation of an aptamer-antigen complex. The proposed biosensor showed excellent sensitivity in detecting P-tau 231, with a broad linear detection range from 10 to 107 pg/mL and a limit of detection (LOD) of 2.31 pg/mL. The recoveries of the biosensor in human serum ranged from 97.59 to 103.26%, demonstrating that the biosensor could be used in complex practical samples. In addition, the results showed that the developed biosensor has good repeatability, reproducibility, and stability, which provides a novel method for the early screening of AD.


Sujet(s)
Maladie d'Alzheimer , Aptamères nucléotidiques , Techniques de biocapteur , Techniques électrochimiques , Or , Limite de détection , Nanoparticules métalliques , Protéines tau , Humains , Maladie d'Alzheimer/sang , Maladie d'Alzheimer/diagnostic , Aptamères nucléotidiques/composition chimique , Protéines tau/sang , Techniques de biocapteur/méthodes , Techniques électrochimiques/méthodes , Techniques électrochimiques/instrumentation , Or/composition chimique , Nanoparticules métalliques/composition chimique , Phosphorylation , Marqueurs biologiques/sang
9.
J Hematop ; 17(2): 63-69, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38652382

RÉSUMÉ

Langerhans cell histiocytosis (LCH) of the stomach is rare. Moreover, it is usually found in pediatric patients with systemic diseases and may be associated with a poor prognosis. Solitary gastric LCH in adults is extremely rare and is often misdiagnosed or missed. The aim of our study was to review cases of gastric LCH and explore the characteristics of the disease further. A retrospective study of all patients admitted with solitary gastric LCH was conducted between 2013 and 2023. Clinical manifestations, endoscopic and pathological features, immunophenotypes, and molecular changes were collected from medical records. We examined four cases (one female, three males) of gastric LCH. The affected patients were between 33 and 70 years of age. Endoscopically, three patients presented with a solitary polyp or elevated lesions, whereas one patient showed no abnormalities. Under a microscope, all cases showed abnormal proliferation of histiocytoid cells infiltrating in a nested or sheet-like fashion. The tumor cells were medium-sized, with a slightly eosinophilic cytoplasm, irregular or renal-shaped nuclei, folded nuclear membranes, visible nuclear grooves, and the infiltration of inflammatory cells in the background. Immunohistochemically, all lesions expressed CD1a, S-100, langerin, and cyclinD1. One case showed diffuse BRAF V600E positivity. Follow-up data were available for all patients from 4 to 36 months, and all patients were alive without recurrence or progress at the time of manuscript preparation. Combined with previously reported data, solitary adult gastric LCH is more common in male patients, most of whom are asymptomatic or exhibit only mild gastrointestinal symptoms, with a good prognosis. Endoscopy often reveals solitary polyps or protruding lesions; rare cases may progress to multifocal/multisystem lesions, necessitating long-term close follow-up.


Sujet(s)
Histiocytose à cellules de Langerhans , Humains , Histiocytose à cellules de Langerhans/anatomopathologie , Histiocytose à cellules de Langerhans/diagnostic , Mâle , Femelle , Adulte , Sujet âgé , Adulte d'âge moyen , Maladies de l'estomac/anatomopathologie , Maladies de l'estomac/diagnostic , Études rétrospectives
10.
J Cutan Pathol ; 51(7): 518-524, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38642003

RÉSUMÉ

Benign natural killer cell enteropathy (NKCE) was first identified in the gastrointestinal (GI) tract. Notably, instances of NKCE have previously been observed at various sites other than the GI tract, including the gallbladder, lymph nodes, esophagus, and female genital tract. Typical NKCE manifests as an NK-cell immunohistological phenotype, with or without TCR rearrangement, and is characterized by the absence of Epstein-Barr virus (EBV) infection and protracted clinical progression. The misdiagnosis of NKT-cell lymphoma has resulted in some patients receiving chemotherapy, while in other instances, the patients' conditions resolved without treatment and showed no evidence of disease recurrence or progression during follow-up examinations. In this paper, we describe a unique case of EBV-negative NKCE occurring in the oral cavity, the first time such a case has been documented. The tumor completely resolved after an excisional biopsy, and subsequent follow-up did not reveal any signs of disease recurrence.


Sujet(s)
Cellules tueuses naturelles , Humains , Mâle , Cellules tueuses naturelles/anatomopathologie , Cellules tueuses naturelles/immunologie , Bouche/anatomopathologie , Sujet âgé
11.
Sci Total Environ ; 929: 172643, 2024 Jun 15.
Article de Anglais | MEDLINE | ID: mdl-38649049

RÉSUMÉ

Particulate inorganic nitrogen aerosols (PIN) significantly influence air pollution and pose health risks worldwide. Despite extensive observations on ammonium (pNH4+) and nitrate (pNO3-) aerosols in various regions, their key sources and mechanisms in the Tibetan Plateau remain poorly understood. To bridge this gap, this study conducted a sampling campaign in Lhasa, the Tibetan Plateau's largest city, with a focus on analyzing the multiple isotopic signatures (δ15N, ∆17O). These isotopes were integrated into a Bayesian mixing model to quantify the source contributions and oxidation pathways for pNH4+ and pNO3-. Our results showed that traffic was the largest contributor to pNH4+ (31.8 %), followed by livestock (25.4 %), waste (21.8 %), and fertilizer (21.0 %), underscoring the impact of vehicular emissions on urban NH3 levels in Lhasa. For pNO3-, coal combustion emerged as the largest contributor (27.3 %), succeeded by biomass burning (26.3 %), traffic emission (25.3 %), and soil emission (21.1 %). In addition, the ∆17O-based model indicated a dominant role of NO2 + OH (52.9 %) in pNO3- production in Lhasa, which was similar to previous observations. However, it should be noted that the NO3 + volatile organic component (VOC) contributed up to 18.5 % to pNO3- production, which was four times higher than the Tibetan Plateau's background regions. Taken together, the multidimensional isotope analysis performed in this study elucidates the pronounced influence of anthropogenic activities on PIN in the atmospheric environment of Lhasa.

12.
Ther Adv Neurol Disord ; 17: 17562864241239117, 2024.
Article de Anglais | MEDLINE | ID: mdl-38616782

RÉSUMÉ

Multiple sclerosis (MS) was defined as a rare disease in China due to its low prevalence. For a long time, interferon ß was the only approved disease-modifying therapy (DMT). Since the first oral DMT was approved in 2018, DMT approval accelerated, and seven DMTs were approved within 5 years. With an increasing number of DMTs being prescribed in clinical practice, it is necessary to discuss the standardized MS treatment algorithms depending on the disease activity and DMT availability. In this review paper, more than 20 Chinese experts in MS have reviewed the therapeutic progress of MS in China and worldwide and discussed algorithms for treating relapsing MS (RMS) based on the available DMTs in China, providing insights for establishing the standardized RMS treatment algorithms in this country.


Treatment algorithms of relapsing multiple sclerosis in China In this review paper, more than 20 Chinese experts in MS have reviewed the therapeutic progress of MS in China and worldwide and discussed algorithms for treating relapsing MS (RMS) based on the available DMTs in China, providing insights for establishing the standardized RMS treatment algorithms in this country: 1) CIS and RRMS account for more than 90% of the MS patients and most of them are mild to moderate; 2) MS patients should initiate DMT treatments as soon as the disease has been diagnosed in order to reduce the risk of disease progression; 3) Patients who have been diagnosed with MS should start treatment with fundamental DMTs unless the disease course has been highly active; 4) MAGNIMS score may be a suitable and simplified assessment tool for measuring treatment response to DMTs; 5) Patients treated with corticosteroids and NSIS should be switched to the standardized DMT treatment during remission in accordance with disease activity.

13.
Small ; 20(33): e2311218, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38533979

RÉSUMÉ

MXene's configuration, whether it is aggregated or dispersed in a monolayer, determines the specific application areas and even greatly influences the intrinsic properties of MXene. However, how to desirably control MXene's configuration is challenging. Here, a simple, additive-free, chemical reaction-free, and scalable strategy to optionally and reversibly regulate MXene's ordered stacking and delamination of MXene aggregates (AM) is reported. Just by controlled freezing of MXene aqueous dispersions, the aggregation percentage, delamination percentage, and interlayer spacing of AM can be finely tuned. Experimental results reveal that the freezing-induced aggregation and delamination effects can be explained by the squeezing action of growing ice grains on the MXene excluded/concentrated between ice grains and the expanding action caused by the ice formation between AM lamellae, respectively. The dominance between them depends on the freezing parameter-influenced ice nucleation sites, numbers, and ice grain sizes. This work not only contributes to the preparation, storage, and practical applications of MXene, but also opens a new and green avenue for controlling materials' assembly structures.

14.
Huan Jing Ke Xue ; 45(3): 1382-1391, 2024 Mar 08.
Article de Chinois | MEDLINE | ID: mdl-38471854

RÉSUMÉ

Tropospheric ozone (O3) is mainly produced through a series of photochemical reactions of nitrogen oxides (NOx) and volatile organic compounds (VOCs). The reaction process presents complex non-linear relationships. In this work, datasets of atmospheric ozone and volatile organic compounds (VOCs) observed during the summer of 2018 in Nanjing were used. Combining with the framework for 0-D atmospheric model-master chemical mechanism (F0AM-MCM), the characteristics of photochemical reactions for ozone (O3) formation in Nanjing during the O3 episode days and non-episode days were investigated. The results showed that φ(O3) and φ(TVOCs) in the O3 episode days were 47.8×10-9 and 49.0×10-9, respectively, exceeding those in the non-episode days by factors of 1.8 and 1.6. Furthermore, F0AM, the empirical kinetic modeling approach (EKMA), and relative incremental reactivity (RIR) were utilized for the calculation of ozone chemical sensitivity. It was found that O3 formation in Nanjing was attributed to both VOCs and NOx limitation. In addition, the modeled ·OH and HO2 concentrations in the O3 episode days were 1.3 and 1.8 times higher than those in the non-episode days. The higher formation and loss rates of ·OH and HO2 were also found during O3 episode days. These findings reflected that the enhancements of atmospheric oxidation capacity resulted in increased production rates of O3, providing an explanation for the enhancements of O3 concentrations in Nanjing during the O3 episode days. The findings also improved the understanding of the O3 photochemical characteristics over Nanjing in the summer during the O3 episode days.

15.
Front Med (Lausanne) ; 11: 1290729, 2024.
Article de Anglais | MEDLINE | ID: mdl-38348336

RÉSUMÉ

Background: Pneumoconiosis is the most important occupational disease all over the world, with high prevalence and mortality. At present, the monitoring of workers exposed to dust and the diagnosis of pneumoconiosis rely on manual interpretation of chest radiographs, which is subjective and low efficiency. With the development of artificial intelligence technology, a more objective and efficient computer aided system for pneumoconiosis diagnosis can be realized. Therefore, the present study reported a novel deep learning (DL) artificial intelligence (AI) system for detecting pneumoconiosis in digital frontal chest radiographs, based on which we aimed to provide references for radiologists. Methods: We annotated 49,872 chest radiographs from patients with pneumoconiosis and workers exposed to dust using a self-developed tool. Next, we used the labeled images to train a convolutional neural network (CNN) algorithm developed for pneumoconiosis screening. Finally, the performance of the trained pneumoconiosis screening model was validated using a validation set containing 495 chest radiographs. Results: Approximately, 51% (25,435/49,872) of the chest radiographs were labeled as normal. Pneumoconiosis was detected in 49% (24,437/49,872) of the labeled radiographs, among which category-1, category-2, and category-3 pneumoconiosis accounted for 53.1% (12,967/24,437), 20.4% (4,987/24,437), and 26.5% (6,483/24,437) of the patients, respectively. The CNN DL algorithm was trained using these data. The validation set of 495 digital radiography chest radiographs included 261 cases of pneumoconiosis and 234 cases of non-pneumoconiosis. As a result, the accuracy of the AI system for pneumoconiosis identification was 95%, the area under the curve was 94.7%, and the sensitivity was 100%. Conclusion: DL algorithm based on CNN helped screen pneumoconiosis in the chest radiographs with high performance; thus, it could be suitable for diagnosing pneumoconiosis automatically and improve the efficiency of radiologists.

16.
Zhongguo Zhen Jiu ; 44(2): 200-203, 2024 Feb 12.
Article de Anglais, Chinois | MEDLINE | ID: mdl-38373767

RÉSUMÉ

This paper systematically reviews the historical evolution of the "Zhibian (BL 54) through Shuidao (ST 28)" needling technique by examining the history of the Mang needle, controversies and positioning of the Zhibian (BL 54), and the formation and essentials of the needling technique. Furthermore, the advantageous disease spectrum of this needling technique is summarized, and speculates on potential advantageous disease spectrum from the neural mechanisms of obtaining qi and achieving efficacy. Lastly, this paper discusses the inadequacies in the research on " Zhibian (BL 54) through Shuidao (ST 28)" needling technique, aiming to provide a comprehensive understanding and reference for further research on this technique.


Sujet(s)
Thérapie par acupuncture , Thérapie par acupuncture/méthodes , , Points d'acupuncture , Aiguilles
17.
Environ Sci Technol ; 58(2): 1244-1254, 2024 Jan 16.
Article de Anglais | MEDLINE | ID: mdl-38178789

RÉSUMÉ

Carbonaceous aerosols (CA) from anthropogenic emissions have been significantly reduced in urban China in recent years. However, the relative contributions of fossil and nonfossil sources to CA in rural and background regions of China remain unclear. In this study, the sources of different carbonaceous fractions in fine aerosols (PM2.5) from five background sites of the China Meteorological Administration Atmosphere Watch Network during the winter of 2019 and 2020 were quantified using radiocarbon (14C) and organic markers. The results showed that nonfossil sources contributed 44-69% to total carbon at these five background sites. Fossil fuel combustion was the predominant source of elemental carbon at all sites (73 ± 12%). Nonfossil sources dominated organic carbon (OC) in these background regions (61 ± 13%), with biomass burning or biogenic-derived secondary organic carbon (SOC) as the most important contributors. However, the relative fossil fuel source to OC in China (39 ± 13%) still exceeds those at other regional/background sites in Asia, Europe, and the USA. SOC dominated the fossil fuel-derived OC, highlighting the impact of regional transport from anthropogenic sources on background aerosol levels. It is therefore imperative to develop and implement aerosol reduction policies and technologies tailored to both the anthropogenic and biogenic emissions to mitigate the environmental and health risks of aerosol pollution across China.


Sujet(s)
Polluants atmosphériques , Polluants atmosphériques/analyse , Matière particulaire/analyse , Fossiles , Surveillance de l'environnement/méthodes , Chine , Carbone , Combustibles fossiles/analyse , Aérosols/analyse , Saisons , Atmosphère
18.
Sci Bull (Beijing) ; 69(7): 978-987, 2024 Apr 15.
Article de Anglais | MEDLINE | ID: mdl-38242834

RÉSUMÉ

Aerosol ammonium (NH4+), mainly produced from the reactions of ammonia (NH3) with acids in the atmosphere, has significant impacts on air pollution, radiative forcing, and human health. Understanding the source and formation mechanism of NH4+ can provide scientific insights into air quality improvements. However, the sources of NH3 in urban areas are not well understood, and few studies focus on NH3/NH4+ at different heights within the atmospheric boundary layer, which hinders a comprehensive understanding of aerosol NH4+. In this study, we perform both field observation and modeling studies (the Community Multiscale Air Quality, CMAQ) to investigate regional NH3 emission sources and vertically resolved NH4+ formation mechanisms during the winter in Beijing. Both stable nitrogen isotope analyses and CMAQ model suggest that combustion-related NH3 emissions, including fossil fuel sources, NH3 slip, and biomass burning, are important sources of aerosol NH4+ with more than 60% contribution occurring on heavily polluted days. In contrast, volatilization-related NH3 sources (livestock breeding, N-fertilizer application, and human waste) are dominant on clean days. Combustion-related NH3 is mostly local from Beijing, and biomass burning is likely an important NH3 source (∼15%-20%) that was previously overlooked. More effective control strategies such as the two-product (e.g., reducing both SO2 and NH3) control policy should be considered to improve air quality.

19.
Arch Anim Breed ; 66(4): 357-368, 2023.
Article de Anglais | MEDLINE | ID: mdl-38111388

RÉSUMÉ

The litter trait is one of the most important economic traits, and increasing litter size is of great economic value in the pig industry. However, the molecular mechanisms underlying pig litter traits remain elusive. To identify molecular markers and candidate genes for pig litter traits, a genome-wide association study (GWAS) and selection signature analysis were conducted in a Yorkshire pig population. A total of 518 producing sows were genotyped with Illumina Porcine SNP 50 BeadChip, and 1969 farrowing records for the total number born (TNB), the number born alive (NBA), piglets born dead (PBD), and litter weight born alive (LWB) were collected. Then, a GWAS was performed for the four litter traits using a repeatability model. Based on the estimated breeding values (EBVs) of TNB, 15 high- and 15 low-prolificacy individuals were selected from the 518 sows to implement selection signature analysis. Subsequently, the selection signatures affecting the litter traits of sows were detected by using two methods including the fixation index (FST) and θπ. Combining the results of the GWAS and selection signature analysis, 20 promising candidate genes (NKAIN2, IGF1R, KISS1R, TYRO3, SPINT1, ADGRF5, APC2, PTBP1, CLCN3, CBR4, HPF1, FAM174A, SCP2, CLIC1, ZFYVE9, SPATA33, KIF5C, EPC2, GABRA2, and GABRA4) were identified. These findings provide novel insights into the genetic basis of pig litter traits and will be helpful for improving the reproductive performances of sows in pig breeding.

20.
Huan Jing Ke Xue ; 44(12): 6486-6494, 2023 Dec 08.
Article de Chinois | MEDLINE | ID: mdl-38098377

RÉSUMÉ

As the main pollutants of secondary inorganic aerosols(SIAs) in fine particulate matter(PM2.5), aerosol ammonium(p-NH4+) plays a significant role in the formation of haze. However, the contribution ratio of each potential source of atmospheric NHx(p-NH4+ and NH3) still remains controversial. In this study, 3 h high-frequency PM2.5 samples were collected in Dongshan, Suzhou during winter and summer in 2015, respectively. Meanwhile, we determined concentrations and δ15N isotope ratios of total nitrogen(TN) and p-NH4+ and quantitatively analyzed formation processes and sources of p-NH4+ based on the Bayesian mixing model(SIAR). SO42-, NO3-, and NH4+ were the main water-soluble ions(WSIs) both in winter and summer, accounting for more than 70% in general. The concentration change trends of PM2.5, TN, and p-NH4+ were consistent, and the concentrations in winter were 2-3 times those in summer. The δ15N-NH4+ value was in direct proportion to the p-NH4+ concentration both in winter and summer. However, δ15N-NH4+ values in winter(-1.7‰±4.3‰) were lower than those in summer(7.8‰±5.9‰). This indicated that the differences in δ15N-NH4+ were caused by different contribution rates of each potential source within each season, whereas it was mainly led by nitrogen isotope fractionation during ammonium-ammonia gas particle distribution in different seasons. The SIAR model calculated that non-agricultural sources were the dominant source of p-NH4+ in Dongshan, with the contribution rate of 59% in winter and 69% in summer, which indicated that NH3 emitted by fossil fuel combustion more easily formed particle aerosol ammonium than that volatilized from agricultural sources.

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